2017-2018学年人教课标高一英语必修3辅导Unit1FestivalsaroundtheworldGRAMMAR

情态动词【归纳】一、can和could★表示能力。can表示现在的能力，could表示过去具有某种能力。如：Mybrothercanspeakfourforeignlanguages.Sophiacouldreadwhenshewasfouryearsold.注意：can表示“能够”时与beableto同义，但can只有过去式could，而beableto可用于各种时态。另外，could表示某人过去有某种能力，而was/wereableto表示某人通过努力、克服困难做成某事，相当于managedto。如：Shewillnotbeabletovisitthehospitaltomorrow.Mikewasanexcellenttennisplayerwhenhewasyoung.Hecouldbeatanybody.Thefirespreadthroughthebuildingveryquickly,butfortunatelyeverybodywasabletoescape.★表示许可。could比can表示的说话语气更委婉。如：Youcanhaveapieceofcakeafteryou'veeatenyourvegetables!CouldIhaveadrinkofwater,please?

★表示可能性。此时could不是can的过去式，它表示推测的可能性比can小。如：Canhestillbealiveafterallthistime?

Ifyou'renotcareful,youcouldgetintoevenworsetrouble.

二、may和might★表示许可或征求对方许可。如：Youmay/mightusemybicyclesolongasyoureturnitbefore12:00.Ican'teat;may/mightIhavealittlebrandy?★表示可能性。might比may语气更不确定，表示的可能性更小。如：Hemay/mightgethereintime,butIcan'tbesure.三、will和would★表示意愿。will表示现在的意愿，有时可用于条件句中，would表示过去的意愿（would如表示现在的意愿，语气较委婉）。如：Iwillhelpherifsheasksusto.Ask,ifyouwill,whotheowneris.

MyfriendaskedifIwouldgowithhim.★表示征求意见或提出请求。will与would均可用于主语是第二人称的疑问句中，表示征求意见或提出请求，此时would并不表示过去，而表示委婉语气。如：—I'mcold.Will/Wouldyoushutthewindow,please?—Certainly.★表示习惯和倾向性。will表示现在的习惯，would表示过去的习惯。如：Shewilllistentorecords,aloneinherroom,forhours.

WhenAnnwasachild,shewouldoftenasksomestrangequestions.四、shall和should★shall在疑问句中用于征求对方意见，主要用于第一人称，也可用于第三人称，意为“要不要，……好吗”。如：Shallwegooutandhaveawalkafterdinner?ShallTomgotherewithmetomorrow?shall还可用于主语是第二、三人称的陈述句中，表示决心、允诺、警告、命令、威胁、规定或义务等。如：Youshallbepunishedifyoubreaktherule.Tellherthatsheshallhavethebiketomorrow.★should表示义务或责任、建议或劝告、推断等。如：Weshouldtakegoodcareofourchildren.Youshouldn'tleaveababyaloneinthehouse.Iwonderwhat'shappenedtoAnnie.Sheshouldbeherebynow.should还可以表示惊讶、失望、遗憾等情感，此时意为“竟会”。如：It'sstrangethatJaneshouldbelate.She'susuallyontime.I'msorrythatyoushouldthinksobadlyofme.五、must和can’t★must可表示“必须做某事”，还可表推测。must表示推测时用于肯定句中，意为“肯定，一定”。如：Imustgotothebanktogetsomemoney.—WhereisTranNguyenfrom?—Iknowthat'saVietnamesename.HemustbefromVietnam.★can't可表否定的推测和判断，意为“不可能”。如：You'vejusthadlunch.Youcan'tbehungry.【即学即练】从括号内选择合适的内容完成下面对话。1.

A:

It’sanationalholidaytomorrowsothere’snopublictransport.HowareJaneandSuegoingtogetthere?B:

Idon’tknow.It’llbedifficult.They________(might,must)takeataxi,butthey________(mightnot,couldnot)e.2.

A:

WhyisJohnwearingsunglasses?It’snotsunny.B:

Iguesshe________(may,must)havesomeproblemwithhiseyes.3.

A:

We’revisitingthe

ForestPark

tomorrowmorning.________(Would,Will)youliketojoinus?B:

I’dloveto,butI________(cannot,couldnot)goouttomorrow.We’regettinganewsofaandthestore________(may,must)bedeliveringittomorrow.4.

A:

Whoisthatmanleavingthelibrary?ItlookslikePeter.B:

It________(may,shall)behisbrother.Theyaresoalikethatpeoplesometimesmistakethemforoneanother.A:

Areyousure?IreallythinkitisPeter.B:

It________(must,can’t)bePeter.He’sinhospital.5.

A:

Whatareyoudoinghere?You________(shall,should)beatthemeetingdowntownatthismoment!B:

Someonecalledandtoldmethemeetingwascancelled.A:

Oh,No!You________(must,can’t)ha